/*
 * Copyright (c) 2003, 2004, 2005 Israfil Consulting Services Corporation
 * Copyright (c) 2003, 2004, 2005 Christian Edward Gruber
 * All Rights Reserved
 * 
 * This software is licensed under the Berkeley Standard Distribution license,
 * (BSD license), as defined below:
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this 
 *    list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice, 
 *    this list of conditions and the following disclaimer in the documentation 
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of Israfil Consulting Services nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software without 
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
 * IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
 * OF SUCH DAMAGE.
 * 
 * $Id: DynamicUtil.java 81 2006-08-03 20:13:29Z cgruber $
 */
package net.israfil.foundation.core;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Utilities used for the implementation of Dynamic and
 * related interfaces.
 * 
 * @author <a href="mailto:cgruber@israfil.net">Christian Edward Gruber </a>
 */
//@Copyright(years={"2003","2004","2005","2006"},owner="Israfil Consulting Services Corporation",license="BSD")
public final class DynamicUtil  {
	private static Logger logger = Logger.getLogger(DynamicUtil.class.getName());

	private DynamicUtil() {}
	
	static Map _primitiveTypes = new HashMap();
	static Map _primitiveTypeEquivalents = new HashMap();
	static Map _boxedTypeEquivalents = new HashMap();
    static {
        _primitiveTypes.put("boolean",boolean.class);
        _primitiveTypeEquivalents.put(Boolean.class,boolean.class);
        _boxedTypeEquivalents.put(boolean.class,Boolean.class);
        _primitiveTypes.put("int",int.class);
        _primitiveTypeEquivalents.put(Integer.class,int.class);
        _boxedTypeEquivalents.put(int.class,Integer.class);
        _primitiveTypes.put("long",long.class);
        _primitiveTypeEquivalents.put(Long.class,long.class);
        _boxedTypeEquivalents.put(long.class,Long.class);
        _primitiveTypes.put("short",short.class);
        _primitiveTypeEquivalents.put(Short.class,short.class);
        _boxedTypeEquivalents.put(short.class,Short.class);
        _primitiveTypes.put("byte",byte.class);
        _primitiveTypeEquivalents.put(Byte.class,byte.class);
        _boxedTypeEquivalents.put(byte.class,Byte.class);
        _primitiveTypes.put("char",char.class);
        _primitiveTypeEquivalents.put(Character.class,char.class);
        _boxedTypeEquivalents.put(char.class,Character.class);
        _primitiveTypes.put("double",double.class);
        _primitiveTypeEquivalents.put(Double.class,double.class);
        _boxedTypeEquivalents.put(double.class,Double.class);
        _primitiveTypes.put("float",float.class);
        _primitiveTypeEquivalents.put(Float.class,float.class);
        _boxedTypeEquivalents.put(float.class,Float.class);
    }
    public static boolean hasPrimitiveTypeEquivalent(Class c) { return _primitiveTypeEquivalents.containsKey(c); }
    public static Class getPrimitiveTypeEquivalent(Class c) { return (Class)_primitiveTypeEquivalents.get(c); }
    public static boolean hasBoxedTypeEquivalent(Class c) { return _boxedTypeEquivalents.containsKey(c); }
    public static Class getBoxedTypeEquivalent(Class c) { return (Class)_boxedTypeEquivalents.get(c); }

    protected static final Map classes = new HashMap();
	public static Set getAllParentTypes(Class c) {
		if (!classes.containsKey(c)) {
			Set parents = new HashSet();
			for (Class cType = c ; cType != Object.class && cType != null ; cType = cType.getSuperclass()) {
				parents.add(cType);
				addSuperInterfaces(parents,cType);
			}
			parents.add(Object.class);
			parents.remove(c);
			classes.put(c,parents);
		}
		return (Set)classes.get(c);
	}
	
	public static void addSuperInterfaces(Set set,Class c) {
		Class[] classes = null;
		if (c == null || (classes = c.getInterfaces()) == null) return;		
		for (int i = 0; i < classes.length; i++) {
			set.add(classes[i]);
			addSuperInterfaces(set,classes[i]);
		}
	}
	
	/** 
	 * Conveniently get a field from an object, automatically trapping
	 * exceptions and returning the Field or null if no such field exists.
	 */
	public static Field getField(Object receiver, String attributeName) {
		Field f = null;
		try {
			f = receiver.getClass().getField(attributeName);
		} catch (NoSuchFieldException e) {
			return null;
		}
		return f;
	}
	
	
	
    /**
     * @see org.israfil.maveric.Dynamic#respondsTo(java.lang.String)
     */
    public static boolean respondsTo(Object receiver, String selector) {
        return (getMethodForSelector(receiver,selector) != null);
    }
    
    public static Method getMethodForSelector(Object receiver, String selector) {
        if (receiver instanceof Class) 
            return getMethodForSelector((Class)receiver,selector);
        return getMethodForSelector(receiver.getClass(),selector);
    }
    
    public static Method getMethodForSelector(Class receiverClass, String selector)  {
    	try {
    		return _getMethodForSelector(receiverClass,selector);
    	} catch (ClassNotFoundException e) { 
    		throw new RuntimeException(e); 
    	} catch (NoSuchMethodException e) { 
    		return null;
    	} 
    }
    
    protected static Method _getMethodForSelector(Class receiverClass, String selector) throws ClassNotFoundException, NoSuchMethodException {
        StringTokenizer st = new StringTokenizer(selector,":");
        Class[] paramTypes = new Class[st.countTokens()-1];
        String methodName = st.nextToken();
        ClassLoader loader = Thread.currentThread().getContextClassLoader();
        for (int i = 0; st.hasMoreTokens(); i++) {
            String className = st.nextToken();
            if (DynamicUtil._primitiveTypes.containsKey(className)) 
                paramTypes[i] = (Class)DynamicUtil._primitiveTypes.get(className);
            else paramTypes[i] = loader.loadClass(className);
        }
        return receiverClass.getMethod(methodName,paramTypes);
    }

    /**
     * @see org.israfil.maveric.Dynamic#perform(java.lang.String, java.lang.Object[])
     */
    public static Object performOn(Object receiver, String selector, Object[] parameters) {
    	if (parameters == null) parameters = new Object[]{};
        Method m = getMethodForSelector(receiver,selector);
        try { 
        	if (m != null) return m.invoke(receiver,parameters); 
        	//else return null;
        	else throw new NoSuchMethodError("No public method defined with selector \""+selector+"\"");
        } catch (InvocationTargetException ite) {
            logger.log(Level.FINE,ite.getClass().getName()+" thrown attempting to invoke selector: " + selector + " on "+receiver,ite); 
            if (ite.getCause() != null) throw new RuntimeException(ite.getCause());
            else throw new RuntimeException(ite);
        } catch (IllegalAccessException iae) {
            logger.log(Level.FINE,iae.getClass().getName()+" thrown attempting to invoke selector: " + selector + " on "+receiver,iae); 		
            throw new RuntimeException(iae);
        } 
    }

    public static Object construct(Class c, Object[] parameters) {
    	Class [] parmTypes = new Class[parameters.length];
    	for (int i = 0; i < parmTypes.length; i++) { parmTypes[i] = parameters[i].getClass(); }
    	try {
    		Constructor constructor = c.getConstructor(parmTypes);
    		return constructor.newInstance(parameters);
        /*
    	} catch (IllegalAccessException iae) { 
            logger.log(Level.FINE,iae.getClass().getName()+" thrown attempting to construct a " + c.getName() + ".", iae); 		
    		return null;
    	} catch (InstantiationException ie) { 
            logger.log(Level.FINE,ie.getClass().getName()+" thrown attempting to construct a " + c.getName() + ".", ie); 		
    		return null;
    	} catch (InvocationTargetException ite) { 
            logger.log(Level.FINE,ite.getClass().getName()+" thrown attempting to construct a " + c.getName() + ".", ite); 		
    		return null;
    	} catch (NoSuchMethodException nsme) { 
            logger.log(Level.FINE,nsme.getClass().getName()+" thrown attempting to construct a " + c.getName() + ".", nsme); 		
    		return null;
    	*/
    	} catch (Exception e) { 
            logger.log(Level.FINE,e.getClass().getName()+" thrown attempting to construct a " + c.getName() + ".", e); 		
    		return null;
    	}
    }

}
